Pump-jack



s. c. CHRISTENSEN. PUMP JACK.

APPLICATION FILED SEPT. 26, 1919. ml. 8,

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A TTORNEX S S C. CHRISTENSEN.

PUMP JACK.

APPLICATION FILED SEPT. 26, 1919. 1,370,518, Patented Mar. 8, 1921.

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FIG. 61

Ar /lJ M/VE/VTOR WITNESSES M J. C CHRMJENSEZM ATTORNEYS SOREN oonnazo CHRISTENSEN, or MAGDALEN'A, New MEXICO,

PUMP-JACK.

Specification of Letters Patent.

v Patented Mar. 8, 1921.

Application filed September 26, 1919. Serial No. 326,503.

To all whom it may concern:

Be it known that I, Sonar: Conan) Cums- TENSEN, a citizen of the United States, and a resident of Magdalena, in the county of Socorro and State of New Mexico, have invented certain new and useful Improvements in Pump-Jacks, of which the followinc is a specification.

My invention is an improvement in pump jacks, and has for its object to provide ajacl: of the character specified especially adapted for converting rotary movement of a windmill, for instance, into reciprocating movement of a pump rod, with a minimum of side play.

In the drawings:

Figure 1 is a front view of the improved jack, with the parts broken away;

Fig. 2 is a view at right angles to Fig. 1;

Fig. 3 is a section on the line 33 of Fig. 1;

Jig. 4.- is a section on the line 4.4 of Fi 2' Tig. 5 is a view of the upper end of the cam plate;

Fig. 6 is a similar view of the lower end of the cam plate;

Fig. 7 is a similar view of the central portion or the cam plate;

Fig. 8 is a view of the upper end of the late, looking at the opposite side from ig. 5.

In the present embodiment of the invention the wind wheel operated shaft 1 is journaled in suitable bearings 2 in a housing, consisting of an upper portion 3 and a lower portion 4 which are detachably connected, the line of separation being at the shaft 1.

The pump rod 5 is mounted to reciprocate in the housing, the said rod passing through a guide 6 on a bracket 7 depending below the housing section 4. It will be noticed, referring to Figs. 1 and 2, that the lower section lot the housing has an inwardly offset portion at its lower end, so that a large portion of the pump rod is outside of the housing section.

At its upper end the rod 5 has a loop 8, and this loop, which is of greatest width at the end remote from its connection with the rod and gradually decreased in width toward the rod, has a perforated lug 9 at its upper end, which fits over a pin 10 on a loop shaped rack bar 11. This rack bar has teeth on its inner edge and these teeth are adapted to engage the teeth of a pinion 12 which is secured to the shaft 1 within the housing.

In order to properly shift the rack bar 11 so that it will be reciprocated by the rotatng movement of the shaft, a cam plate 13 is provided, and the said cam plate has loop shaped tracks 1 1 and 14, respectively, and each of these has a switch at its outer end. Each of these tracks is a continuous groove in the cam plate, and each track is engaged by a roller 15 on the rack bar. I At the outer end of each trackway there IS provided a switch 16 in the form of a tongue which is pivoted to the cam plate to swing freely at its outer end. Referring to Fig. 5, it will be seen that the trackways 14 and 14 are similar, each having one side straight and in line with the same side of the other trackway. The remote ends of the trackways are rounded and the straight portion of each trackway communicates with the other portion by an inclined portion 17. The tongues 16 are substantially triangular, having their bases pivoted at the ends of the portion of the cam plate which divides the trackway into the two portions eXtending alongside of each other.

Each of these switch tongues or points is normally held in a certain position by a spring 18,4011 the opposite face of the cam plate from the switch points switch point or tongue 16 is held out of contact with the adjacent inclined surface 17 of the cam plate. while the lower switch tongue is normally held in contact with the inclined surface 17, the arrangement at each point or tongue being such that when the tongue is swung toward the inclined portion or away therefrom, as the case may be, by a roller 15, the spring will return the point to original position.

In operation, when the shaft 1 rotates to the right, that is, with the crank 21 moving toward the observer, the rack bar, as shown in Fig. 7 will move upward, the teeth of the pinion engaging the teeth of the right side member of the rack bar. The roller 15 at the lower end of the rack bar will be in engagement with the left hand portion of the cam groove 14* and the roller 15 at the top will be in engagement with the corresponding portion of the trackway 14. The upper roller will move upward into the upper end of the straight portion of the trackway, moving the switch The upperpoint 16 aside, that is, moving it into eontact with the inclined portion 17 of the trackway.

As soon as the roller 15 passes the switch point 16, the switch is swung back in contaet with the straight side of the trackway by the spring 18. The roller 15 at the lower end of the rack bar will move upward and around the rounded upper end of the lower trackway and down the inclined portion of the traekway, passing the switch and moving into the lower end of the straight portion of the trackway. As soon as the lower roller 15 passes the free end of the switch, the switch swings back into contact with the lower inclined portion of the trackway 17 and the roller passes up the straight portion of the trackway, thus making the en tire lift straight up.

At the end of its movement in each direction the rack bar will be shifted by the switch points, so that the pinion will always be in engagement with the teeth of the rack bar, and the rack bar will travel first upward and then downward, going the full length of the stroke of the piston rod and converting the rotating movement of the shaft into reciprocating movement of the ro The lower section 4 of the housing reservoir for lubricant, and it will be evident that the dipping of the rack bar into the lubricant in the reservoir will keep the parts continuously lubricated. The upper end of the cam plate 13 has threaded stems 23 which extend through openings in the upper section 3 of the housing and they are engaged by nuts 24 tohold the housing in place.

I claim:

1. A pump jack comprising in combinais a' outwardly offset portion connecting the ends of the strai ht portion, the rack bar havlng a roller for engaging each traekway, and means for constrainlng said rollers to travel. in corresponding portions of the trackway during the vertical movement of the rack, said means coinprlsmg switch tongues at the remote ends of the trackways and springs normally pressing the tongues in opposite directions.

2; A pump jack comprising in combination with the motor shaft carrying a pinion, of a loop shaped rack bar having internal teeth adapted to be engaged by the pinion, said rack bar having at one end means for connecting the bar with a pump rod, and means controlled by the movement of the rack bar for retaining the teeth thereof in continuous mesh with the teeth of the pinion, said means comprising a cam plate having trackways at its ends, each track- 'way consisting of a straight portion and an outwardly offset portion connecting the ends of the straight portion, the rack bar having a roller for engaging each traekway, and means for constraining said rollers to travel in corresponding portions of the traclzways during the vertical movement of the rack.

SDREN CONRAD CHRISTENSEN, 

